yescrypt_crack - Yescrypt Hash Cracker

cyclone

Title: Yescrypt Hash Cracker
Author: cyclone
URL: https://github.com/cyclone-github/yescrypt_crack
Description:

pcfg-go - The Fast PCFG

Probabilistic Context-Free Grammar (PCFG) password generator - Pure Go Edition
- pcfg-go is a Pure Go rewrite of the Python3 pcfg_cracker
- The goal of this Go implementation is to provide a substantial performance improvement for both trainer and guesser over the original Python3 version, while also adding features such as supporting $HEX[] input and multi-byte character support — which is not implemented in the Pure C pcfg_guesser
- Credits for the original python3 pcfg_cracker belong to the author @lakiw
- Rules trained by pcfg_trainer are compatible with hashcat's new PCFG -a 4 attack mode. See the hashcat PCFG implementation commit for details.

Install

pcfg_trainer:

go install -ldflags="-s -w" github.com/cyclone-github/pcfg-go/cmd/pcfg_trainer@main

pcfg_guesser:

go install -ldflags="-s -w" github.com/cyclone-github/pcfg-go/cmd/pcfg_guesser@main

Additions & improvements

Performance — ~53.94× faster pcfg_trainer and ~12.16× faster pcfg_guesser vs Python 3 (see Benchmarks below)
$HEX[] input — Trainer accepts $HEX encoded passwords in the training wordlist (multi-byte support)
Ctrl+C handling — Pressing Ctrl+C auto-saves the session in pcfg_guesser
Multi-keyboard layouts — QWERTY, AZERTY, QWERTZ, Dvorak, JCUKEN (Russian Cyrillic)
Expanded TLD list — Legacy TLDs, ccTLDs, gTLDs (.info, .xyz, .app, .dev, etc.), and short TLDs (.co, .io, .ai, .me, .gg); improves both website and email detection
Improved website detection — Broader URL/prefix detection (http://, https://, www., etc.) and host extraction
Multi-threaded architecture — pcfg_guesser is multi-threaded for increased performance
Compiled binary — No fuss; pcfg-go uses compiled binaries for speed and easy deployment

Benchmarks on rockyou training set

`pcfg_trainer -r rockyou -t rockyou.txt`

Python3 trainer: 13m21s (801s)
Go pcfg_trainer: 14.85s
Speedup: ~53.94×

`pcfg_guesser -r rockyou -n 100000000` (100 million guesses written to stdout)

Python3 pcfg_guesser: 195.5s
Go pcfg_guesser: 16.08s
Speedup: ~12.16×

Usage

pcfg_trainer

Train a new ruleset from wordlist:

pcfg_trainer -r rule_name -t wordlist.txt

pcfg_guesser

Generate guesses from a trained ruleset:

pcfg_guesser -r rule_name

Session save/restore:

pcfg_guesser -r rule_name -s my_session   # save to my_session.sav on exit
pcfg_guesser -r rule_name -s my_session -l # load and resume

Press Ctrl+C to save session and exit.

Piping into hashcat

pcfg_guesser -r rule_name -s my_session | hashcat -m 0 hashes.txt...

Using trained rules with hashcat -a 4 PCFG mode

hashcat -m 0 -a 4 hashes.txt path_to_pcfg_rule_dir ...

Flags

pcfg_trainer

pcfg-go vs pcfg-python3 flags

Go	Python3	Description
-r	--rule	Ruleset name
-t	--training	Training wordlist (required)
-e	--encoding	File encoding
-C	--comments	Config comments
-S	--save_sensitive	Save emails, URLs
-p	--prefixcount	Lines prefixed with count
-n	--ngram	OMEN ngram size (2-5)
-a	--alphabet	Alphabet size for Markov
-c	--coverage	PCFG vs OMEN coverage
-m	--multiword	Pre-train multiword file
-h	--help	Help
-version	--version	Version info

pcfg_guesser

pcfg-go vs pcfg-python3 flags

Go	Python3	Description
-r	--rule	Ruleset name
-s	--session	Session name
-l	--load	Load previous session
-n	--limit	Max guesses
-b	--skip_brute	Skip OMEN/Markov
-a	--all_lower	No case mangling
-d	--debug	Debug output
-h	--help	Help
-version	--version	Version info

Compile from source (linux)

Requires Go and Git.

git clone https://github.com/cyclone-github/pcfg-go.git
cd pcfg-go
go mod tidy
mkdir -p bin
go build -ldflags="-s -w" -o bin/pcfg_trainer ./cmd/pcfg_trainer
go build -ldflags="-s -w" -o bin/pcfg_guesser ./cmd/pcfg_guesser

Install to $GOPATH/bin:

go install -ldflags="-s -w" ./cmd/pcfg_trainer
go install -ldflags="-s -w" ./cmd/pcfg_guesser

cyclone

Source code v0.2.0; 2025-03-06 uploaded to GitHub.
https://github.com/cyclone-github/yescrypt_crack

cyclone

Release v0.3.1; 2026-08-08
https://github.com/cyclone-github/yescrypt_crack/releases/tag/v0.3.1

add gost-yescrypt support

cyclone

v0.4.0-dev adds OpenCL support. Thanks to @64nickel for testing on his 12x 4090 cluster.
https://infosec.exchange/@cyclone/117134021102477783

Partly9642

Hi @cyclone . When trying to install the tool either with go install or build it, i got the binary, which gives errors for my AMD GPUS:

❯ yescrypt_crack -h 2507_yescrypt.hash -w ~/org/11_total.txt
 -------------------------------------------------- 
|            Cyclone's Yescrypt Cracker            |
| https://github.com/cyclone-github/yescrypt_crack |
 -------------------------------------------------- 

Hash file:      2507_yescrypt.hash
Total Hashes:   2
CPU Threads:    16
Wordlist:       /home/otto/org/11_total.txt
Backend:        GPU
GPU selection:  all
GPU batch:      864
2026/08/31 09:14:01 Counting wordlist lines...
2026/08/31 09:14:01 Tuning GPU...
2026/08/31 09:14:02 OpenCL GPU 1 (gfx1101) self-test failed: GPU self-test configure failed: OpenCL kernel build failed (-11) [-cl-std=CL1.2 -DYC_N=4096 -DYC_R=32]: ld.lld: error: undefined hidden symbol: block_mix_classic
>>> referenced by /tmp/comgr-818210-13-4404ef/input/linked.o:(yescrypt_init)
>>> referenced by /tmp/comgr-818210-13-4404ef/input/linked.o:(yescrypt_init)
>>> referenced by /tmp/comgr-818210-13-4404ef/input/linked.o:(yescrypt_init)
>>> referenced 1 more times

ld.lld: error: undefined hidden symbol: smix_rw
>>> referenced by /tmp/comgr-818210-13-4404ef/input/linked.o:(yescrypt_init)
>>> referenced by /tmp/comgr-818210-13-4404ef/input/linked.o:(yescrypt_init)
Error: Creating the executable from LLVM IRs failed.
2026/08/31 09:14:02 OpenCL GPU 0 (gfx1201) self-test failed: GPU self-test configure failed: OpenCL kernel build failed (-11) [-cl-std=CL1.2 -DYC_N=4096 -DYC_R=32]: ld.lld: error: undefined hidden symbol: block_mix_classic
>>> referenced by /tmp/comgr-818210-15-ce2159/input/linked.o:(yescrypt_init)
>>> referenced by /tmp/comgr-818210-15-ce2159/input/linked.o:(yescrypt_init)
>>> referenced by /tmp/comgr-818210-15-ce2159/input/linked.o:(yescrypt_init)
>>> referenced 1 more times

ld.lld: error: undefined hidden symbol: smix_rw
>>> referenced by /tmp/comgr-818210-15-ce2159/input/linked.o:(yescrypt_init)
>>> referenced by /tmp/comgr-818210-15-ce2159/input/linked.o:(yescrypt_init)
Error: Creating the executable from LLVM IRs failed.
2026/08/31 09:14:02 GPU tuning failed; falling back to CPU
2026/08/31 09:14:02 Working...

cyclone

@partly9642
This is a GPU sanity-check failure. When this happens, yescrypt_crack falls back to CPU mode. The error may indicate an issue with the AMD OpenCL implementation or local OpenCL environment, but further testing is needed to confirm what's actually going on.

Please verify that:

You are running yescrypt_crack on native Linux or Windows, not WSL or another emulated environment
Your AMD GPU and OpenCL drivers are up to date and working correctly
The GPU has sufficient VRAM, since yescrypt is memory intensive

If everything checks out and the error persists, please open a GitHub issue:
https://github.com/cyclone-github/yescrypt_crack/issues

Please include:

GPU model and VRAM
AMD driver/OpenCL/ROCm version
Host OS/version
Full yescrypt_crack error/output

hashpwn